HV830 High Voltage EL Lamp Driver IC Features General Description ► ► ► ► ► ► The Supertex HV830 is a high-voltage driver designed for driving EL lamps of up to 50nF. EL lamps greater than 50nF can be driven for applications not requiring high brightness. The input supply voltage range is from 2.0V to 9.5V. The device uses a single inductor and a minimum number of passive components. The nominal regulated output voltage that is applied to the EL lamp is ±100V. The chip can be enabled by connecting the resistors on the RSW-Osc and REL-Osc pins to the VDD pin, and disabled when connected to GND. ► ► ► ► ► Processed with HVCMOS® technology 2.0V to 9.5V operating supply voltage DC to AC conversion 200V peak-to-peak typical output voltage Large output load capability typically 50nF Permits the use of high-resistance elastomeric lamp components Adjustable output lamp frequency to control lamp color,lamp life, and power consumption Adjustable converter frequency to eliminate harmonics and optimize power consumption Enable/disable function Low current draw under no load condition Very low standby current - 30nA typical Applications ► ► ► ► ► ► Handheld personal computers Electronic personal organizers GPS units Pagers Cellular phones Portable instrumentation The HV830 has two internal oscillators, a switching MOSFET and a high-voltage EL lamp driver. The frequency of the switching converter MOSFET is set by an external resistor connected between the RSW-Osc and the VDD pins. The EL lamp driver frequency is set by an external resistor connected between the REL-Osc and the VDD pins. An external inductor is connected between the LX and VDD pins. A 0.01µF to 0.1µF capacitor is connected between the CS pin and the GND. The EL lamp is connected between the VA and VB pins. The switching MOSFET charges the external inductor and discharges it into the CS capacitor. The voltage at CS will start to increase. Once the voltage at CS reaches a nominal value of 100V, the switching MOSFET is turned OFF to conserve power. The output pins VA and VB are configured as an Hbridge and are switched in opposite states to achieve 200V peak-to-peak across the EL lamp. Block Diagram LX VDD CS RSW-Osc ENABLE Switch Osc Q VA GND + Disable C Q _ VREF Output Osc Q VB REL-Osc Q HV830 Ordering Information Package Option Device HV830 Pin Configuration 8-Lead SOIC HV830LG VDD 1 8 REL-Osc RSW-Osc 2 7 VA CS 3 6 VB LX 4 5 GND HV830LG-G -G indicates the package is RoHS compliant - “Green” 8-Lead SOIC (top view) Product Marking Absolute Maximum Ratings Parameter Value HV830 Supply voltage, VDD -0.5 to +10V LLLL Output voltage, VCS -0.5 to +120V Power dissipation Storage temperature Y = Last Digit of Year Sealed WW = Week Sealed L = Lot Number = “Green” Packaging YWW 400mW -65OC to +150OC Operating temperature -25OC to +85OC Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. Continuous operation of the device at the absolute rating level may affect device reliability. All voltages are referenced to device ground. Recommended Operating Conditions Symbol Parameter VDD Supply voltage fEL VA-B output drive frequency TA Operating temperature DC Electrical Characteristics (V IN VCS VA - VB Typ Max Unit 2.0 - 9.5 V --- - - 1.5 KHz --- -25 - +85 O C Conditions --- = 3.0V, RSW = 1.0MΩ, REL = 3.3MΩ, TA = 25°C unless otherwise specified) Symbol Parameter RDS(ON) Min Min Typ Max Unit - 2.0 4.0 Ω I = 100mA Output voltage - regulation 90 100 110 V VDD = 2.0V to 9.5V Output peak-to-peak voltage 180 200 220 V VDD = 2.0V to 9.5V ON resistance of switching transistor Conditions IDDQ Quiescent VDD current - diabled - 30 - nA RSW-Osc = Low IDD VDD supply current - 100 150 µA VDD = 3.0V. See Fig.1 IIN Input current including inductor current - 35 40 mA VDD = 3.0V. See Fig.1 VCS Output voltage on VCS - 95 - V VDD = 3.0V. See Fig.1 fEL VA - VB output drive frequency 220 250 280 Hz VDD = 3.0V. See Fig.1 fSW Inductor switching frequency 55 65 75 KHz VDD = 3.0V. See Fig.1 D Switching transistor duty cycle - 88 - % 2 --- HV830 Fig.1: Test Circuit, VIN = 3.0V ON = VDD OFF = 0V 3.3MΩ 1 VDD REL-Osc 2 RSW-Osc VA 7 3 CS VB 6 4 LX GND 5 8 1.0MΩ 220µH1 VDD = VIN = 3.0V BAS21LT1 0.1µF2 0.01µF 200V 1nF 3.0 square inch lamp. HV830 Notes: 1. Murata part # LQH4N221K04 (DC resistanve < 5.4Ω). 2. Larger values may be required depending upon supply impedence. Enable/Disable Configuration The HV830 can be easily enabled and disabled via a logic control signal on the RSW and REL resistors as shown in Fig.4 below. The control signal can be from a microprocessor. RSW and REL are typically very high values, therefore, only 10’s of microamperes will be drawn from the logic signal when it is at a logic high (enable) state. When the microprocessor signal is high the device is enabled and when the signal is low, it is disabled. Fig. 2: Enable/Disable Configuration ON =VDD Remote Enable REL OFF = 0V 1 VDD REL-Osc 2 RSW-Osc VA 7 3 CS VB 6 4 LX GND 5 8 RSW LX + VIN = VDD BAS21LT1 4.7µF 15V CS 200V 1.0nF Enable/Disable Table RSW Resistor HV830 VDD Enable 0V Disable 3 HV830 EL Lamp HV830 Fig. 3 Split Supply Configuration Remote Enable ON = VDD OFF = 0V REL VDD = Regulated Voltage 1 VDD REL-Osc 2 RSW-Osc 8 RSW LX VA 7 EL Lamp + VIN = Battery Voltage 3 CS VB 6 4 LX GND 5 BAS21LT1 – 0.1µF* HV830 CS 200V 1nF * Larger values may be required depending upon supply impedence. Split Supply Configuration Using a Single Cell (1.5V) Battery The HV830 can also be used for handheld devices operating from a single cell 1.5V battery where a regulated voltage is available. This is shown in Fig. 3. The regulated voltage can be used to run the internal logic of the HV830. The amount of current necessary to run the internal logic is typically 100µA at a VDD of 3.0V. Therefore, the regulated voltage could easily provide the current without being loaded down. The HV830 used in this configuration can also be enabled/disabled via logic control signal on the RSW and REL resistors as shown in Fig.2. Split Supply Configuration for Battery Voltages of Higher than 9.5V Fig. 3 can also be used with high battery voltages, such as 12V, as long as the input voltage, VDD, to the HV830 device is within its specifications of 2.0V to 9.5V. 4 HV830 External Component Description External Component Description Diode Fast reverse recovery diode, BAS21LT1 or equivalent. CS Capacitor 0.01µF to 0.1µF, 200V capacitor to GND is used to store the energy transferred from the inductor. REL-Osc The EL lamp frequency is controlled via an external REL resistor connected between REL-Osc and VDD pins of the device. The lamp frequency increases as REL decreases. As the EL lamp frequency increases, the amount of current drawn from the battery will increase and the output voltage VCS will decrease. The color of the EL lamp is dependent upon its frequency. A 3.3MΩ resistor would provide lamp frequency of 220 to 280Hz. Decreasing the REL-Osc by a factor of 2 will increase the lamp frequency by a factor of 2. RSW-Osc The switching frequency of the converter is controlled via an external resistor, RSW between the RSW-Osc and VDD pins of the device. The switching frequency increases as RSW decreases. With a given inductor, as the switching frequency increases, the amount of current drawn from the battery will decrease and the output voltage, VCS, will also decrease. A 1nF capacitor is recommended between the RSW-Osc pin and GND when a 0.01µF CS capacitor is used. This capacitor is used to shunt any switching noise that may couple into the RSW-Osc pin. The CSW capaciCSW Capacitor tor may also be needed when driving large EL lamp due to increase in switching noise. A CSW larger than 1.0nF is not recommended. LX Inductor The inductor LX is used to boost the low input voltage by inductive flyback. When the internal switch is on, the inductor is being charged. When the internal switch is off, the charge stored in the inductor will be transferred to the high voltage capacitor CS. The energy stored in the capacitor is connected to the internal H-bridge and therefore to the EL lamp. In general, smaller value inductors, which can handle more current, are more suitable to drive larger size lamps. As the inductor value decreases, the switching frequency of the inductor (controlled by RSW) should be increased to avoid saturation. 220µH Murata inductors with 5.4Ω series DC resistance is typically recommended. For inductors with the same inductance value but with lower series DC resistance, lower RSW value is needed to prevent high current draw and inductor saturation. Lamp As the EL lamp size increases, more current will be drawn from the battery to maintain high voltage across the EL lamp. The input power, (VIN x IIN), will also increase. If the input power is greater than the power dissipation of the package (400mW), an external resistor in series with one side of the lamp is recommended to help reduce the package power dissipation. 5 HV830 8-Lead SOIC (Narrow Body) Package Outline (LG) 4.9x3.9mm body, 1.75mm height (max), 1.27mm pitch D θ1 8 E E1 L2 Note 1 (Index Area D/2 x E1/2) L 1 θ L1 Top View Gauge Plane Seating Plane View B A View B Note 1 h h A2 A Seating Plane b e A1 A Side View View A-A Note 1: This chamfer feature is optional. If it is not present, then a Pin 1 identifier must be located in the index area indicated.The Pin 1 identifier may be either a mold, or an embedded metal or marked feature. Symbol A MIN Dimension (mm) 1.35 A1 0.10 A2 1.25 b 0.31 D 4.80 E E1 5.80 e 3.80 NOM - - - - 4.90 6.00 3.90 MAX 1.75 0.25 1.50 0.51 5.00 6.20 4.00 h 0.25 1.27 BSC L L1 L2 0.40 - - 0.50 1.27 θ 0 1.04 REF 0.25 BSC O θ1 5O - - 8O 15O JEDEC Registration MS-012, Variation AA, Issue E, Sept. 2005. Drawings not to scale. (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Doc. # DSFP-HV830 C081507 6